Conformal symmetry at lightlike distances and asymptotic behaviour of electromagnetic form factors

Using conformal symmetry for the operator product of the hadronic electromagnetic current and the pion interpolating field, at lightlike distances, we connect the behaviour of the structure function in the scaling limit to the on-mass-shell asymptotic behaviour of the electromagnetic pion form factor. Our results are based on the analysis of the dimension spectrum of local operators appearing in the operator product expansion and on the assumption of precocious scaling. As an application of our results, predictions on the asymptotic behaviour of the e.m. pion form factor as well as for the threshold behaviour of the structure function for the singly inclusive π production in e⁺e^- annihilation, are given.